Lord Hereford is the eldest son of the late 18th Viscount Hereford (d 25 Feb 2004) and of Susan, Viscountess Hereford, of Ascott, Warwickshire, and Louisa is the younger daughter of (Christopher) William Knight, of Holland Park, London, by his wife the former Jonkvrouwe Sylvia Caroline dau of Jonkheer Emile van Lennep, of The Hague.

Wm Knight is the son of the Hon Priscilla DODSON (dau of 2nd Baron Monk Bretton and Ruth, dau of Hon Charles BRAND scion of the Viscounts Hampden) and Maj Claude Thorburn Knight, scion of the LG family THORBURN formerly of Craigerne.